1. Field of the Invention
The present invention relates to a damper device for use on the door of a container to apply damping forces to the angular movement of the door in terminal ranges of opening and closing movements of the door, or for use on an electrically powered tool such as an electrically powered saw or plane to reduce shocks in terminal ranges of reciprocating movements thereof.
2. Description of the Related Art
Heretofore, some containers are equipped with a damper device mounted on the door for preventing the door from banging against the door frame when the door is closed. Since the damper device operates only when the door is closed, however, the damper device is not active when the door is quickly opened. When the door is quickly opened, therefore, the door tends to hit a stop, producing undesirable noise or causing damage to itself or the stop. For producing a damping action in a terminal range of the opening movement of the door, the door needs to incorporate another separate damper device separately from the existing damper device which operates only when the door is closed.
There has not been known any example in which the above damper device is applied to a reciprocally movable electrically powered tool. Heretofore, it has been customary for the user of a reciprocally movable electrically powered tool to empirically control forces produced by the tool in terminal regions of its reciprocating actions to avoid unwanted impacts or damage to the tool. However, controlling forces produced by the tool in terminal regions of its reciprocating actions needs a skilled experience on the part of the user, and is physically fatiguing to the user.
Installing two damper devices on one door is highly costly. In addition, it is a complex task to install two damper devices on one door and also to perform maintenance on the two damper devices mounted on the door. There has been a demand for a single damper device which is capable of producing a damping force in both terminal ranges of opening and closing movements of a door on which the damper device is installed.